There are certifications related to clinical research but are not useful without having any research related experience and are very costly for most of the times and are not required by the recruiters, only thing they need is the experience. CROs and sponsors only care about experience as sponsors rule to CROs and they are investing money for the clinical trials and studies. So they want people with experience for safe studies and well invested money.
There are many opportunities in clinical industry and in almost every country, every position is available and are running their trials all over the world and doing different studies and have a lot of studies to work on and sponsors are investing money and more opportunities are coming.
There are also many universities offering certifications in several research fields which give you experience and better understanding of the field because no certificate and degree matter if you know nothing about clinical industry. Certificated only gives you experience which can be gained through entry level positions.